Operators of plant, equipment, and building services (whether by appointment or by default) need to know how to do the job properly. They need written instructions, as do the maintenance fitters who will occasionally visit and may inadvertently wreak havoc with your systems.
Your operating instruction manual needs a reference section laying out the preferred standard settings for all controls. It needs to state how the plant is to be run; in a building, for example, it should say what seasonal changes should be made to the deployment of heating boilers.